The County Road A disposal site, located on the Bad River Indian Reservation, Ashland County, Wisconsin, contains papermill sludge generated by a former mill in the City of Ashland. Since the time of disposal (1968.1970) the site has been the subject of investigations by the U.S. Bureau of Indian Affairs, the U.S. Environmental Protection Agency, and private consultants. During 1997. 1998, an investigation was conducted by the U.S. Geological Survey, in cooperation with the U.S. Environmental Protection Agency and the Natural Resources Department of the Bad River Indian Tribe, to evaluate the hydrogeology and groundwater quality of the disposal site, particularly with respect to the hydraulic connection between two ponds at the site and the shallow ground-waterflow system. Additional monitoring wells and well points were installed, and additional hydrogeologic, ground-water quality, and geophysical data were collected. The data from this and previous studies were integrated and interpreted.
Data collected during this investigation indicate the ponds are hydraulically connected to the shallow ground-water system. Pond stage and meteorological data collected from May 6 through August 18, 1998 indicate evaporation and seepage from Pond A, the southernmost pond, to ground water accounted for the measured declines in pond stage. Seepage was estimated to be from 0.008.0.012 feet per day over the area of Pond A. Increases in the stage of Pond A following precipitation events resulted in increases in the hydraulic head in pond sediments as measured in well point WP-2 in the southwestern area of the pond. Hydraulic gradients were consistently downward across the pond sediments, ranging from 0.24 to 0.38 feet per foot. Although the estimated vertical hydraulic conductivity of the pond sediments is low (0.021.0.050 feet per day), limited flow occurs through the pond sediments. A complex hydraulic connection between Pond A and the shallow sediments was defined by changes in water levels in well points in and adjacent to the pond. Neutron logs indicated that the sediments under Pond A were saturated.
The hydraulic connection between the ponds and the shallow ground-water system is supported by water-quality data. Inorganic and organic constituents of the papermill sludge have been detected in water-quality samples collected from on-site monitoring wells. Concentrations of acetone, aluminum, antimony, 2-butanone, lead, sodium, and possibly cobalt exceeded background concentrations for this site. Concentrations of inorganic constituents, with the exception of potassium and zinc, were considerably lower in samples from local residential wells than those from monitoring wells. Elevated concentrations of potassium and zinc, however, are consistent with concentrations measured previously in other wells and springs on the Bad River Indian Reservation. None of the organic compounds identified in the papermill sludge have been detected in water sampled from the residential wells.
west of the hatch ery, flows from northwest to southeast, and discharges to streams, lakes, springs, and flowing wells.
Springs and flowing wells are common at the hatchery because of upward hydraulic gradients in the sand and gravel aquifer. Total flow from springs and wells at the hatchery is approximately 3 million gallons per day. The recharge area for the ground water discharging at the hatchery extends at least 5 miles to the west. Ground water may flow from or under the Pine River to wells and springs at the hatchery.
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USGS Numbered Series
An alternative regionalization scheme for defining nutrient criteria for rivers and streams